A detent is a catch or a lever mechanism that defines resting positions as one part of an assembly moves relative to another part. Conventional detent devices typically rely on mechanical means, such as a lever and socket combination, to restrict the movement of the system in defining the resting positions. One type of detent is a rotational device that divides the rotation of a wheel, shaft or hinge into discreet increments where the fixed discreet increments define the detent positions. These mechanical systems commonly employ a small gravity or spring actuated lever paired with a notched shaft to help define the detent positions.
In addition to defining detent positions, some detent devices offer self-centering forces that help to align and move the detent bodies into detent positions when the detent bodies are perturbed from their detent positions. In mechanical detents, centering mechanisms can include a wide diversity of contraptions including springs, levers, balls, etc. As a rotating mechanism is rotated to misalign two detent bodies from a detent position, a self-centering force will arise to slow the rotation and position the rotating detent bodies back into alignment. When a perturbing force is large enough to overcome the self-centering force to move a body completely out of the force field of a first detent position, another self-centering force will arise to place the bodies into another, typically adjacent, detent position force field, thereby moving the bodies into the other detent position.
Existing detent mechanisms therefore typically require two bodies with surfaces that slide against each other. Friction between these two surfaces and other environmental effects cause the force profile offered by the detents to change over time. This may result in less than optimum performance as the device wears. Because these types of detent devices also involve multiple parts such as shafts, sockets, levers, springs, etc., tolerance requirements can also add to the complexity and cost of the device manufacture and assembly. There is therefore a need for detent systems with improved performance and manufacturability.